The world is filled with display screens, computer monitors, image projectors, street signs, electronic bulletin boards, etc. All of these are examples of “screens” that display images, video, and other content. The ability to accurately detect the boundaries of such screens and separate them from the background has many application including, but not limited to, Automatic Content Recognition (ACR) of TV and video content, augmented reality experience to merge screen content and virtual objects, reading dynamic street signs, transmitting and syncing messages through large electronic bulletin boards (e.g., score boards in a stadium, departure/arrival screens in airports), and recognizing the identity of an exhibition in museums or other show rooms.